Occurrence and human health risk of wastewater-derived pharmaceuticals in a drinking water source for Shanghai, East China.

Pharmaceuticals are heavily used to improve human and animal health, resulting in the frequent contamination of aquatic environments with pharmaceutical residues, which has raised considerable concern in recent years. When inadequately removed from drinking water in water treatment plants, pharmaceuticals can have potential toxic effects on human health. This study investigated the spatial distributions and seasonal variations of five pharmaceuticals, including ibuprofen (IBP), ketoprofen (KEP), naproxen (NPX), diclofenac (DFC), and clofibric acid (CA), in the Huangpu River system (a drinking water source for Shanghai) over a period of almost two years as well as the associated risk to human health for different age groups. All of the targets were ubiquitous in the river water, with levels decreasing in the following order: KEP (mean: 28.6 ng/L)≈IBP (23.3 ng/L)>DFC (13.6 ng/L)≈NPX (12.3 ng/L)>CA (1.6ng/L). The concentrations of all of the investigated compounds were at the low or medium end of the global range. The upstream tributaries contained lower IBP but higher NPX than did the mainstream and downstream tributaries. However, no significant variations were found in the levels of KEP, DFC, or CA at the different sampling sites. Except for CA in the mainstream, significantly higher pharmaceutical levels were observed in the dry season than in the wet season. Overall, a very low risk of the selected pharmaceuticals for human health via drinking water was observed, but future studies are needed to examine the fate and chronic effects of all pharmaceuticals in aquatic environments. To our knowledge, this is the first report to investigate the human health risk of pharmaceuticals in raw drinking water in China.